Indirect exposure pathways

Indirect exposure pathways

For aquatic disposal, the most likely human pathway is an indirect exposure

pathway through consumption of fish or shellfish (Figure 10). Therefore, this

section provides details and examples for assessing the pathway. Within this

pathway, the likely exposure route for humans to contaminated sediments and

surface water is the ingestion of fish or shellfish that have accumulated these

compounds. This exposure pathway fulfills the criteria for a complete exposure

pathway (as described above) because:

a. There is a source of contaminants C the sediments at the dredged material

management site.

b. There is a transfer mechanism between the sediments and the seafood C

bioaccumulation.

c. There are exposure points where contact occurs C the commercially or

recreationally caught seafood which have been exposed to contaminants

from the management site.

d. There is an exposure route C the consumption of this seafood.

Figure 10. Example of a conceptual model showing direct and indirect exposure pathways for human

health

Characterization of this exposure setting for seafood ingestion requires:

a. Defining the exposed human population.

Chapter 4 Human Health Risk Assessment